Electrode holder



Dec. 19, 1939. w. A. ROBB v ELECTRODE HOLDER Filed Oct. 30, 19s?Patented Dec. 19, 1939 ;UNITED STATES PATENT OFFICE ELECTRODE HOLDER-Wilbur A. Robb, Huntington Park, Calif. Y Application October so, 1937,.SerialNo. 171,873

-7 Claims. (01. 176-119)" My invention relates to electrode holders, andmore particularly to holders for carbon electrodes for motion pictureprojecting machines.

An important object of the invention is to providemeans for holding sucha carbon electrode until it is almost completely consumed. Under presentpractice, carbon electrodes, that have been used for about three orfour-reels of moving picture film, often have to be thrown away eventhough there is still suflicient carbon left to last for another reel offilm.

The reason for this lies in the construction and arrangement of carbonholders on motion picture projecting machines now in general use. It isan object ofmy invention to provide a carbon holder that will reducethis waste to a minimum, whereby considerable saving can be effected bymoving picture theaters in the quantity of carbon electrodes utilized inthe operation of their projection machines.

Still another object is to provide such a holder for the positive carbonof a motion picture proj ection machine, which carbon is consumed fasterthan the negative one.

The invention also comprises novel details of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description.

In the drawing, like reference characters designate similar parts in theseveral views.

Figure l is an elevation of an electrode carrier of a motion pictureprojection machine, to which carrier has been applied my electrodeholder.

Figure 2 is a section through a stem of my holder, taken on the line 22of Figure 1, looking in the direction of the arrows.

Figure 3 is a section through my holder, taken on the line 3-3 of Figure1, looking in the direction of the arrows.

Figure 4 is a section through my holder, taken on the line fl4 of Figure1, looking in the direction of the arrows. b

Figure 5 is a bottom view of my electrode holder.

Figure 6 is a perspective view of my electrode holder.

Figure '7 is-a perspective view of a portion of a motion pictureprojection machine.

Referring more in detail to the drawing, the reference numeral Idesignates a support on a motion picture projection machine for apositive carbon electrode holder. A fixed jaw 8 is mount- ,ed on thesupport, while a movable jaw 9 is disposed in clamping arrangement withthe jaw 8.

An aperturejd block. H is mounted on the support 7 at therear of thejaws.8,. 9.

A sleeve 12 onithe support provides a bearing for a handle l3. Thehandle is connected to operate the movable, clamping jaw 9. An arm I 4on' 5 the support! maintains the sleeve I2 on the support in relativelyfixed position. The handle l3 and the sleeve l2 have-a threadedvengagement (not shown). I

A conductive cable vIi": is connected with the 10 support 1, to conductpositive electrical current to the holder. l

A stationaryelectrode guide I6 has a notched top. I! for directingpositive carbon electrode l8 as it is-fed forward into operativeassociation 15 with a negative carbonelectrode [9. An ash receiver 20isdisposed beneath the ends of the two electrodes l8, Hi, to catch ashesfalling therefrom.

The support, Tis a movable support, to feed forward the positive carbonelectrode. Conventional parts of a motion picture projection machine areillustrated in relatively light, unshaded lines, in the drawing. Sincethe details of construction of. the ordinary motion picture projectionmachine are well known in the trade,'further .illustration anddescription are deemed unnecessary.' I

My holder, generally designated it], includes a stem 22 that issubstantially square insection. The rear end of the stem 22 is insertedin the requir,e.side openings Zlto be cutout at the sides 28 of the head24. These side cut-away portions 21 are of sufiicient size for acylindrically shaped carbon electrode in the holder Ill to be eitherfiush with the sides 28 of the head, or to extend beyond the sides 28.The function of this arrangement is that the carbon electrode I 8 maythereby ride against the surfaces of the notch I1 even though my holderis employed.

Continuing rearward from the recess 26, the head 24, the collar 23 andthe stem 22 have a continuous slot 29.

In the use of my invention, when a carbon electrode has been used untilits length has been substantially reduced, the end of the remainder isinserted into the recess 26 and the rear end of the stem 22 is insertedin the aperture in the block It. The split, forward end of the stemaperture in the block H and the forward end of is disposed between thejaws 8, 9. Rotation of handle l3 causes the movable jaw 9 to be movedtoward the fixed jaw 8, thus clamping the portions of the split end ofthe holder about the end of the carbon electrode. The pressure of themovable jaw upon the split end places the latter under pressure, thusmaintaining my holder in place.

It will be noted that my holder does not interfere with the carbonseating in the notch 11, for the carbon engages the notch ll'through theslots 21.

When the holder Ii! has been fed forward to its limit (as shown inbroken lines in Figure 1), the collar 23 engages the outer face of theguide l6, thus preventing further forward movement of the support 1.

While I have illustrated and described what I now regard as thepreferred embodiment of my invention, the construction is, of course,subject to modifications without departing from the spirit of myinvention. 1, therefore, do not wish to restrict myself to theparticular form of construction illustrated and described, but desire toavail myself of all modifications which may fall within the scope of theappended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In a motion picture projection machine having a guide for anelectrode and having a movable support for feeding the electrode whilebeing directed by the guide, a holder on the support, and a member onthe holder for receiving the electrode, the member being arranged tomove along the guide during advancing movement of the support, and aside of the member being cut away sufficiently for the portion of thecarbon within said member to ride directly on the guide during saidadvancing movement of the support.

2. In a motion picture projection machine having a guide for anelectrode and having a movable support for feeding the electrode whilebeing directed by the guide, a holder on the support, and a member onthe holder for receiving the electrode, the member substantiallyconforming with the shape of the guide and being arranged to advancealong the guide during advancing movement of the support, and a side ofthe member being cut away for the carbon to ride directly on the guideduring said advancing movement of the support.

3. In a motion picture projection machine having an angularly notchedguide for an electrode and having a movable support for feeding theelectrode while being directed by the guide, a holder on the support,and an angularly shaped member on the holder substantially conformingwith the shape of the notch in the guide and being arranged to advancealong the guide during advancing movement of the support, and theangularly arranged faces of the member being cut away for the carbon toride directly on the guide during said advancing movement of thesupport.

4. In a motion picture projection machine having a guide for anelectrode and having a movable support for feeding the electrode whilebeing directed by the guide, a holder on the support, a collar on theholder arranged to engage the guide and thereby limitthe movement of theholder, and means on the holder for gripping an end of an electrode,said means being arranged ahead of the collar and being disposed to movealong the guide.

5. In a motion picture projection machine having a guide for anelectrode, having a movable support for feeding the electrode whilebeing directed by the guide, and having relatively fixed and movablejaws, a holder on the support, a collar on the holder arranged to engagethe guide and thereby limit the movement of the holder, a head on theholder shaped to move along the guide until the collar engages same, thehead and collar being split and the portion of the holder at the end ofthe split being of unitary construction to provide resilience to theholder, the head being recessed to receive the end of an electrode, andthe holder being arranged between the fixed and movable jaws of themachine for said jaws to clamp the split head upon an end of anelectrode.

6. In a motion picture projection machine having a guide for anelectrode and having a movable support for feeding the electrode whilebeing directed by the guide, a holder on the support for receiving theelectrode, the holder being arranged to move along the guide duringadvancing movement of the support, the holder having a recess to receivean electrode and the recess having an opening in a side thereof, and anelectrode disposed in the recess and extending through the opening inthe side of the recess at least to the outer surface of the holder.

'7. In a motion picture projection machine having a support forprogressively feeding an electrode and having a guide provided with adifferently shaped notch than the electrode to direct the electrode, aholder on the support for reeciving the electrode, the holder beingarranged to bottom in the notch, the holder having a recess to receivean electrode and the recess having an opening in a side thereof, and anelectrode disposed in the recess and extending through the opening inthe side of the recess and into engagement with the notch.

WILBUR A. ROBB.

